First data on Deeply Virtual Compton Scattering with CLAS12 at 10.6 GeV Electron Beam

Apr 11, 2019, 9:04 AM
17m
Rettorato - Aula Principi d'Acaja

Rettorato - Aula Principi d'Acaja

via Verdi, 8 Turin
Parallel Session Talk WG6: Spin and 3D structure WG6: Spin and 3D structure

Speaker

Francesco Bossu (CEA-Saclay)

Description

Generalized Parton Distributions (GPDs) provide the opportunity to obtain a 3-dimensional description of a nucleon in terms of its constituent partons. Moreover, GPDs are related, via QCD-based sum rules, to total angular momentum, mass and pressure distributions inside the nucleon. GPDs are experimentally accessible via the deeply virtual Compton scattering (DVCS), i.e. the absorption of a highly virtual photon by the proton and the subsequent emission of a high-energy photon.

At Jefferson Lab, the brand new CLAS12 spectrometer has been commissioned and has collected its first DVCS data with a 10.6 GeV continuous electron beam in winter 2017 - spring 2018. Its central part, containing the cylindrical silicon and micromegas trackers within a 5T-solenoidal field surrounding the liquid hydrogen target, is ideal to detect the recoil proton of a DVCS event. The forward detectors, placed in a toroidal magnetic field, detect the associated scattered electron and high energy photon. A first look at the data collected so far with CLAS12 for DVCS studies on unpolarized proton target will be presented together with projections for the full run.

Primary author

Francesco Bossu (CEA-Saclay)

Presentation materials